Cationic oxidation bases, their use for the oxidation dyeing of keratin fibres, dyeing compositions and dyeing methods

ABSTRACT

The invention concerns novel pyrazolo[1,5-a]pyrimidines comprising at least a cationic group Z, Z being selected among quaternized aliphatic chains, aliphatic chains comprising at least a quaternized cycle, and their use as oxidation base for dyeing keratin fibers, the dyeing compositions containing them, and the oxidation dyeing methods using them.

The invention relates to novel pyrazolo[1,5-a]pyrimidines comprising atleast one cationic group Z, Z being selected from quaternized aliphaticchains, aliphatic chains containing at least one quaternized saturatedring and aliphatic chains containing at least one quaternizedunsaturated ring, to their use as oxidation base for the oxidationdyeing of keratinous fibres, to the dyeing compositions comprising them,and to the methods of oxidation dyeing which employ them.

It is known to dye keratinous fibres, and especially human hair, withdyeing compositions comprising oxidation dye precursors, especiallyortho- or para-phenylenediamines, ortho- or para-aminophenols, andheterocyclic compounds such as diaminopyrazole derivatives, which arereferred to generally as oxidation bases. The oxidation dye precursorsor oxidation bases are colourless or slightly coloured compounds which,when combined with oxidizing products, have the capacity to give rise tocoloured and colouring compounds by virtue of a process of oxidativecondensation.

It is also known that the shades obtained with these oxidation bases maybe varied by combining them with couplers or coloration modifiers, thelatter being selected in particular from aromatic meta-diamines,meta-aminophenols, meta-diphenols and certain heterocyclic compounds.

The variety of molecules employed as oxidation bases and couplers makesit possible to obtain a rich palette of colours.

The so-called permanent coloration obtained by virtue of these oxidationdyes is required, moreover, to satisfy acertain number of requirements.Hence it must have no toxicological drawbacks, must allow shades of thedesired intensity to be obtained, and must have good resistance toexternal agents (light, inclement weather, washing, permanent-waving,perspiration and friction).

The dyes must also allow white hair to be covered and, finally, theymust be as unselective as possible; in other words, they must allow thesmallest possible differences in coloration to be produced over theentire length of a single keratinous fibre, which may indeed besensitized (i.e. damaged) differently between its tip and its root.

The applicant has now discovered, completely unexpectedly andsurprisingly, that new pyrazolo[1,5-a]pyrimidines of formula (I) definedbelow, comprising at least one cationic group Z, Z being selected fromquaternized aliphatic chains, aliphatic chains containing at least onequaternized saturated ring and aliphatic chains containing at least onequaternized unsaturated ring are not only suitable for use as oxidationdye precursors, but also make it possible to obtain dyeing compositionswhich lead to intense colorations in a wide palette of colours and haveexcellent properties of resistance to the various treatments which thekeratinous fibres may undergo.

It is these discoveries which form the basis of the present invention.

The invention therefore provides, firstly, novel compounds of formula(I) below, and their addition salts with an acid:

in which:

R₁, R₂ and R₃, which may be identical or different, represent a hydrogenatom; a halogen atom; a group Z; a (C₁-C₆ alkyl)carbonyl radical; anamino(C₁-C₆ alkyl)carbonyl radical; an N-Z-amino(C₁-C₆ alkyl)carbonylradical; an N-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; anN,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; an amino(C₁-C₆alkyl)carbonyl(C₁-C₆ alkyl) radical; an N-Z-amino(C₁-C₆alkyl)carbonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl(C₁-C₆ alkyl) radical; a carboxyl radical; a (C₁-C₆alkyl)carboxyl radical; a (C₁-C₆ alkyl)sulphonyl radical; anaminosulphonyl radical; an N-Z-aminosulphonyl radical; an N-(C₁-C₆alkyl)aminosulphonyl radical; an N,N-di(C₁-C₆ alkyl)-aminosulphonylradical; an aminosulphonyl(C₁-C₆ alkyl) radical; anN-Z-aminosulphonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; a carbamyl radical; anN-(C₁-C₆ alkyl)carbamyl radical; an N,N-di(C₁-C₆ alkyl)carbamyl radical;a carbamyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl)radical; an N,N-di(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl) radical; a C₁-C₆alkyl radical; a hydroxyl radical; a nitro radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; a C₁-C₆ trifluoroalkyl radical; a cyanoradical; a group OR₆ or SR₆; an amino radical; an N-(C₆-C₆ alkyl)aminoradical; an N,N-di(C₁-C₆ alkyl)amino radical (where the two alkylsubstituents may form a 5- or 6-membered ring); an N-hydroxy(C₁-C₆alkyl)amino radical; an N,N-bis(hydroxy(C₁-C₆ alkyl))amino radical; anN-polyhydroxy(C₂-C₆ alkyl)amino radical; an N,N-bis(polyhydroxy(C₂-C₆alkyl))amino radical; an amino(C₁-C₆ alkyl)amino radical in which theterminal amino group is unsubstituted or substituted by one or two C₁-C₆alkyl radicals, where the said alkyl radicals may form a saturated orunsaturated, 5- or 6-membered ring; an amino group protected by a (C₁-C₆alkyl)carbonyl, trifluoro(C₁-C₆ alkyl)carbonyl, amino(C₁-C₆alkyl)carbonyl, N-Z-amino(C₁-C₆ alkyl)-carbonyl, N-(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl, N,N-di(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl or formyl radical or by a group Z;

R₆ denotes a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; aC₂-C₆ polyhydroxyalkyl radical; a group Z; a C₁-C₆ (C₁-C₆ alkoxy)alkylradical; an aryl radical; a benzyl radical; a C₁-C₆ carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a C₁-C₆ cyanoalkylradical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ trifluoroalkyl radical; a C₁-C₆ aminosulphonylalkylradical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)carbonylalkyl radical; a C₁-C₆ aminoalkyl radical; a C₁-C₆aminoalkyl radical whose amine is substituted by one or two identical ordifferent radicals selected from C₁-C₆ alkyl, monohydroxy(C₁-C₆ alkyl),polyhydroxy(C₂-C₆ alkyl), (C₁-C₆ alkyl)-carbonyl, formyl,trifluoro(C₁-C₆ alkyl)carbonyl and (C₁-C₆ alkyl)sulphonyl radicals or bya group Z;

A represents a group —NR₄R₅ or a hydroxyl radical;

R₄ and R₅, which are identical or different, represent a hydrogen atom;a group Z; a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; aC₂-C₆ polyhydroxyalkyl radical; a C₁-C₆ (C₁-C₆ alkoxy)alkyl radical; anaryl radical; a benzyl radical; a C₁-C₆ cyanoalkyl radical; a C₁-C₆carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆ alkyl)carbamylalkyl radical; aC₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkyl radical; a C₁-C₆thiocarbamylalkyl radical; a C₁-C₆ trifluoroalkyl radical; a C₁-C₆sulphoalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a C₁-C₆(C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆ aminosulphonylalkylradical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)-aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carbonylalkylradical; a C₁-C₆ aminoalkyl radical; a C₁-C₆ aminoalkyl radical whoseamine is substituted by one or two identical or different radicalsselected from C₁-C₆ alkyl, C₁-C₆ monohydroxyalkyl, C₂-C₆polyhydroxyalkyl, (C₁-C₆ alkyl)carbonyl, (C₁-C₆ alkyl)sulphonyl, formyland trifluoro(C₁-C₆ alkyl)carbonyl radicals or by a group Z; one andonly one of the radicals R₄ and R₅ may also represent a (C₁-C₆alkyl)carbonyl; formyl; trifluoro(C₁-C₆ alkyl)carbonyl; amino(C₁-C₆alkyl)carbonyl, N-Z-amino (C₁-C₆ alkyl)carbonyl; N-(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl; or N,N-di(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl radical;

Z is selected from the unsaturated cationic groups of formulae (II) and(III) below and the saturated cationic groups of formula (IV) below:

in which:

D is a linker which represents an alkyl chain containing preferably 1 to14 carbon atoms, is linear or branched and may be interrupted by one ormore heteroatoms such as oxygen, sulphur or nitrogen atoms and may besubstituted by one or more hydroxyl or C₁-C₆ alkoxy radicals, and maycarry one or more ketone functions;

the ring members E, G, J, L and M, which are identical or different,represent a carbon, oxygen, sulphur or nitrogen atom;

n is an integer between 0 and 4, inclusively;

m is an integer between 0 and 5, inclusively;

the radicals R, which are identical or different, represent a group Z, ahalogen atom, a hydroxyl radical, a C₁-C₆ alkyl radical, a C₁-C₆monohydroxyalkyl radical, a C₂-C₆ polyhydroxyalkyl radical, a nitroradical, a cyano radical, a C₁-C₆ cyanoalkyl radical, a C₁-C₆ alkoxyradical, a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical, an amido radical,an aldehydo radical, a carboxyl radical, a C₁-C₆ alkylcarbonyl radical,a thio radical, a C₁-C₆ thioalkyl radical, a (C₁-C₆ alkyl)thio radical,an amino radical, an amino radical protected by a (C₁-C₆ alkyl)carbonyl,carbamyl or (C₁-C₆ alkyl)sulphonyl radical; a group NHR″ or NR″R′″ inwhich R″ and R′″, which are identical or different, represent a C₁-C₆alkyl radical, a C₁-C₆ monohydroxyalkyl radical or a C₂-C₆polyhydroxyalkyl radical;

R₇ represents a C₁-C₆ alkyl radical, a C₁-C₆ monohydroxyalkyl radical, aC₂-C₆ polyhydroxyalkyl radical, a C₁-C₆ cyanoalkyl radical, a C₁-C₆tri(C₁-C₆ alkyl)silanealkyl radical, a C₁-C₆ (C₁-C₆ alkoxy)alkylradical, a carbamyl(C₁-C₆ alkyl) radical, a C₁-C₆ (C₁-C₆alkyl)carboxyalkyl radical, a benzyl radical, or a group Z;

R₈, R₉ and R₁₀, which are identical or different, represent a C₁-C₆alkyl radical, a C₁-C₆ monohydroxyalkyl radical, a C₂-C₆polyhydroxyalkyl radical, a C₁-C₆ (C₁-C₆ alkoxy)alkyl radical, a C₁-C₆cyanoalkyl radical, an aryl radical, a benzyl radical, a C₁-C₆amidoalkyl radical, a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical or aC₁-C₆ aminoalkyl radical whose amine is protected by a (C₁-C₆alkyl)carbonyl, amido, carboxyl or (C₁-C₆ alkyl)sulphonyl radical; twoof the radicals R₈, R₉ and R₁₀ may also form, together with the nitrogenatom to which they are attached, a saturated 5- or 6-memberedcarbon-containing ring or one containing one or more heteroatoms suchas, for example, a pyrrolidine ring, a piperidine ring, a piperazinering or a morpholine ring, it being possible for the said ring to beunsubstituted or substituted by a halogen atom, a hydroxyl radical, aC₁-C₆ alkyl radical, a C₁-C₆ monohydroxyalkyl radical, a C₂-C₆polyhydroxyalkyl radical, a nitro radical, a cyano radical, a C₁-C₆cyanoalkyl radical, a C₁-C₆ alkoxy radical, a C₁-C₆ tri(C₁-C₆alkyl)silanealkyl radical, an amido radical, an aldehydo radical, acarboxyl radical, a C₁-C₆ ketoalkyl radical, a thio radical, a C₁-C₆thioalkyl radical, a (C₁-C₆ alkyl)thio radical, an amino radical, or anamino radical protected by a (C₁-C₆ alkyl)carbonyl, carbamyl or (C₁-C₆alkyl)sulphonyl radical; one of the radicals R₈, R₉ and R₁₀ may alsorepresent a second group Z, identical to or different from the firstgroup Z;

R₁₁ represents a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical;a C₂-C₆ polyhydroxyalkyl radical; an aryl radical; a benzyl radical; aC₁-C₆ aminoalkyl radical, a C₁-C₆ aminoalkyl radical whose amine isprotected by a (C₁-C₆ alkyl)carbonyl, carbamyl or (C₁-C₆ alkyl)sulphonylradical; a C₁-C₆ carboxyalkyl radical; a C₁-C₆ cyanoalkyl radical; aC₁-C₆ carbamylalkyl radical; a C₁-C₆ trifluoroalkyl radical; a C₁-C₆tri(C₁-C₆ alkyl)silanealkyl radical; a C₁-C₆ sulphonamidoalkyl radical;a C₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a C₁-C₆ (C₁-C₆alkyl)-sulphinylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl) sulphonylalkylradical; a C₁-C₆ (C₁-C₆ alkyl)ketoalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆ alkyl) sulphonamidoalkylradical;

a and y are integers equal to 0 or 1; with the following conditions:

in the unsaturated cationic groups of formula (II):

when a=0, the linker D is attached to the nitrogen atom,

when a=1, the linker D is attached to one of the ring members E, G, J orL,

y can adopt the value 1 only

1) when the ring members E, G, J and L simultaneously represent a carbonatom and when the radical R₇ is carried by the nitrogen atom of theunsaturated ring; or else

2) when at least one of the ring members E, G, J and L represents anitrogen atom to which the radical R₇ is attached;

in the unsaturated cationic groups of formula (III):

when a=0, the linker D is attached to the nitrogen atom,

when a=1, the linker D is attached to one of the ring members E, G, J, Lor M,

y can adopt the value 1 only when at least one of the ring members E, G,J, L and M represents a divalent atom and when the radical R₇ is carriedby the nitrogen atom of the unsaturated ring;

in the cationic groups of formula (IV):

when a=0, then the linker D is attached to the nitrogen atom whichcarries the radicals R₈ to R₁₀,

when a=1, then two of the radicals R₈ to R₁₀, together with the nitrogenatom to which they are attached, form a 5- or 6-membered saturated ringas defined above, and the linker D is carried by a carbon atom of thesaid saturated ring;

X⁻ represents a monovalent or divalent anion and is selected preferablyfrom a halogen atom such as chlorine, bromine, fluorine or iodine, ahydroxide, a hydrogen sulphate or a C₁-C₆ alkyl sulphate such as, forexample, a methyl sulphate or an ethyl sulphate; with the proviso thatthe number of cationic groups Z is at least 1.

As indicated above, the colorations obtained with the oxidation dyeingcomposition in accordance with the invention are intense and make itpossible to obtain a wide palette of colours. Moreover, they exhibitexcellent properties of resistance with respect to the action of variousexternal agents (light, inclement weather, washing, permanent-waving,perspiration, friction). These properties are particularly remarkable asregards notably, the resistance of the colorations obtained with respectto the action of light, washing, permanent-waving and perspiration.

In the formula (I) above, the alkyl and alkoxy radicals may be linear orbranched.

Among the rings of the unsaturated groups Z of formula (II) above,mention may be made in particular, by way of example, of pyrrole,imidazole, pyrazole, oxazole, thiazole and triazole rings.

Among the rings of the unsaturated groups Z of formula (III) above,mention may be made in particular, by way of example, of pyridine,pyrimidine, pyrazine, oxazine and triazine rings.

Among the compounds of formula (I) above, mention may be made inparticular of the following:

3-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-(2-hydroxyethyl)-3H-imidazol-1-iumchloride,

3-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylcarbamoyl)-methyl)-1-methyl-3H-imidazol-1-iumchloride,

3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]-pyrimidin-6-ylmethyl)-1-methylpyridiniummethyl sulphate,

3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]-pyrimidin-6-ylmethyl)-1-(2-hydroxyethyl)pyridiniumchloride,

2-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)methyl]-1,3-dimethyl-3H-imidazol-1-iummethyl sulphate,

3-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)-methyl]-1-methylpyridiniummethyl sulphate,

3-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)-methyl]-1-methylpyridiniummethyl sulphate,

2-(3,7-diamino-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1,3-dimethyl-3H-imidazol-1-iummethyl sulphate,

2-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]-pyrimidin-6-ylmethyl)-1,3-dimethyl-3H-imidazol-1-iummethyl sulphate,

2-(3,7-diaminopyrazolo[1,5-a]pyrimidin-2-yl)-1-methylpyridinium methylsulphate,

[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]trimethylammoniumchloride,

[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]trimethylammoniummethyl sulphate,

1-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-methylpiperidiniumchloride,

1-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-methylpiperidiniummethyl sulphate,

4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-4-methylmorpholin-4-iumchloride,

4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-4-methylmorpholin-4-iummethyl sulphate, and their addition salts with an acid.

Among these compounds of formula (I), more particular preference isgiven to the following:

3-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-(2-hydroxyethyl)-3H-imidazol-1-iumchloride,

3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]-pyrimidin-6-ylmethyl)-1-methylpyridiniummethyl sulphate,

3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]-pyrimidin-6-ylmethyl)-1-(2-hydroxyethyl)pyridiniumchloride,

3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]-pyrimidin-6-ylmethyl)-1-methylpyridiniumchloride,

4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-4-methylmorpholin-4-iumchloride,

4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-4-methylmorpholin-4-iummethyl sulphate, and their addition salts with an acid.

The compounds of formula (I) in accordance with the invention may bereadily obtained in accordance with well-known methods of the prior art:

firstly by reduction of the corresponding cationic nitroso or nitrocompounds. In this case, reduction to the corresponding primary aromaticamine is carried out in accordance with conventional methods (J. Lehmmanin Houben-Weyl, “Methoden der Organischen Chemie”, volume IV/1c:Reduction 1 page 491 to 537, 1980). The methods which are preferred inaccordance with the invention involve metals such as Zn, Sn or Fe in anacidic medium such as aqueous hydrochloric acid or aqueous acetic acidin the presence or absence of a cosolvent such as methanol, ethanol ortetrahydrofuran. Catalytic hydrogenation is a preferred reduction methodin accordance with the invention. This catalytic hydrogenation makes useof metals such as palladium, platinum or nickel. More particularlystill, preference is given to palladium on carbon or to Raney nickel, orelse to oxides such as PtO₂ in solvents such as ethanol, ethanol,tetrahydrofuran or ethyl acetate in the presence or absence of an acidsuch as, for example, acetic acid. These catalytic reductions may alsobe carried out with formic acid in the presence of a trialkylamine suchas triethylamine or with ammonium formate in the place of gaseoushydrogen. (S. Ram, R. E. Ehrenkaufer, Synthesis, 1988,91);

secondly, by reduction of the corresponding cationic azo compounds(reductive cleavage). Reduction to the corresponding primary aromaticamine is carried out in accordance with conventional methods (J. Lehmmanin Houben-Weyl, “Methoden der Organischen Chemie”, volume IV/1c:Reduction 1 page 551 to 553, 1980; E. C. Taylor et al., J. Amer. Chem.Soc. 80, 421, 1958).

This step of reduction (to obtain a primary aromatic amine), which givesthe synthesized compound its character as an oxidizable compound(oxidation base), and is followed or not by formation of a salt, is ingeneral, for convenience, the last step of the synthesis.

This reduction may occur earlier on in the sequence of reactions leadingto the preparation of the compounds of formula (I), and in accordancewith well-known processes it is then necessary to “protect” the primaryamine created (for example by a step of acetylation,benzenesulphonation, etc.), to carry out subsequently the desiredsubstitution(s) or modification(s) (including the quaternization), andto end with the “deprotection” (generally in an acidic medium) of theamine function.

When the synthesis is at an end, the compounds of formula (I) inaccordance with the invention may, if appropriate, be recovered bywell-known methods of the prior art, such as crystallization ordistillation.

The invention additionally provides for the use of the compounds offormula (I) in accordance with the invention as oxidation base for theoxidation dyeing of keratinous fibres and, in particular, of humankeratinous fibres such as the hair.

The invention also provides a composition for the oxidation dyeing ofkeratinous fibres and, in particular, of human keratinous fibres such asthe hair, characterized in that it comprises as oxidation base, in amedium appropriate for dyeing, at least one compound of formula (I) inaccordance with the invention.

The compound or compounds of formula (I) in accordance with theinvention represent(s) preferably from 0.0005 to 12% by weight,approximately, of the total weight of the dyeing composition, and, morepreferably still, from 0.005 to 6% by weight, approximately, of thisweight.

The medium appropriate for dyeing (or vehicle) generally consists ofwater or a mixture of water and at least one organic solvent forsolubilizing the compounds which would not be sufficiently soluble inwater. By way of organic solvent, mention may be made, for example, ofC₁-C₄ lower alkanols, such as ethanol and isopropanol; glycerol; glycolsand glycol ethers, such as 2-butoxyethanol, propylene glycol, propyleneglycol monomethyl ether, diethylene glycol monoethyl and monomethylether, and also aromatic alcohols such as benzyl alcohol orphenoxyethanol, similar products and mixtures thereof.

The solvents may be present in proportions of preferably between 1 and40% by weight, approximately, relative to the total weight of the dyeingcomposition, and still more preferably between 5 and 30% by weight,approximately.

The pH of the dyeing composition according to the invention is generallybetween 3 and 12, approximately, and preferably between 5 and 11,approximately. It may be adjusted to the desired value by means ofacidifying or basifying agents which are commonly employed in the dyeingof keratinous fibres.

Among the acidifying agents, mention may be made, by way of example, ofmineral acids or organic acids such as hydrochloric acid,orthophosphoric acid, sulphuric acid, carboxylic acids such as aceticacid, tartaric acid, citric acid and lactic acid, and sulphonic acids.

Among the basifying agents, mention may be made, by way of example, ofaqueous ammonia, alkali metal carbonates, alkanolamines such as mono-,di- and triethanolamines and their derivatives, sodium hydroxide orpotassium hydroxide, and the compounds of formula (V) below:

in which W is a propylene residue optionally substituted by a hydroxylgroup or a C₁-C₆ alkyl radical; and R₁₂, R₁₃, R₁₄ and R₁₅, which areidentical or different, represent a hydrogen atom or a C₁-C₆ alkyl orC₁-C₆ hydroxyalkyl radical.

Furthermore, the dyeing composition according to the invention maycomprise, in addition to the dyes defined above, at least one additionaloxidation base, which may be selected from the oxidation basesconventionally used in oxidation dyeing and among which mention may bemade in particular of para-phenylenediamines, bisphenylalkylenediamines,para-aminophenols; ortho-aminophenols and heterocyclic bases other thanthe compounds of formula (I).

Among the para-phenylenediamines, mention may be made more particularly,by way of example, of para-phenylenediamine, para-tolylenediamine,2,6-dimethyl-para-phenylenediamine,2-β-hydroxyethyl-para-phenylenediamine,2-n-propyl-para-phenylenediamine, 2-isopropyl-para-phenylenediamine,N-(β-hydroxypropyl)-para-phenylenediamine,N,N-bis(β-hydroxyethyl)-para-phenylenediamine,4-amino-N-(β-methoxyethyl)aniline, the para-phenylenediamines describedin French Patent Application FR 2 630 438, and their addition salts withan acid.

Among the bisphenylalkylenediamines, mention may be made moreparticularly, by way of example, ofN,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)ethylenediamine,N,N′-bis(4-aminophenyl)-tetramethylenediamine,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4-aminophenyl)tetramethylenediamine,N,N′-bis(4-methylaminophenyl)tetramethylenediamine,N,N′-bis(ethyl)-N,N′-bis(4′-amino-3′-methylphenyl)-ethylenediamine, andtheir addition salts with an acid.

Among the para-aminophenols, mention may be made more particularly, byway of example, of para-aminophenol, 4-amino-3-methylphenol,4-amino-3-fluorophenol, 4-amino-3-hydroxymethylphenol,4-amino-2-methylphenol, 4-amino-2-hydroxymethylphenol,4-amino-2-methoxymethylphenol, 4-amino-2-aminomethylphenol,4-amino-2-(β-hydroxyethylaminomethyl)phenol, and their addition saltswith an acid.

Among the ortho-aminophenols, mention may be made more particularly, byway of example, of 2-aminophenol, 2-amino-5-methylphenol,2-amino-6-ethylphenol, 5-acetamido-2-aminophenol, and their additionsalts with an acid.

Among the heterocyclic bases, mention may be made more particularly, byway of example, of the pyridine derivatives, the non-cationic pyrimidinederivatives and the pyrazole derivatives.

Among the pyridine derivatives, mention may be made more particularly ofthe compounds described, for example, in Patents GB 1 026 978 and GB 1153 196, such as 2,5-diaminopyridine,2-(4-methoxyphenyl)amino-3-aminopyridine, 2,3-diamino-6-methoxypyridine,2-(β-methoxyethyl)amino-3-amino-6-methoxypyridine, 3,4-diaminopyridine,and their addition salts with an acid.

Among the pyrimidine derivatives, mention may be made more particularlyof the compounds described, roe for example, in German Patent DE 2 359399 or Japanese Patents JP 88-169 571 and JP 91-10659 or PatentApplication WO 96/15765, such as 2,4,5,6-tetraaminopyrimidine,4-hydroxy-2,5,6-triaminopyrimidine, 2-hydroxy-4,5,6-triaminopyrimidine,2,4-dihydroxy-5,6-diaminopyrimidine, 2,5,6-triaminopyrimidine, and thepyrazolo-pyrimidine derivatives such as those mentioned in PatentApplication FR-A-2 750 048 and among which mention may be made ofpyrazolo[1,5-a]pyrimidine-3,7-diamine;2,5-dimethylpyrazolo[1,5-a]pyrimidine-3,7-diamine;pyrazolo[1,5-a]pyrimidine-3,5-diamine;2,7-dimethylpyrazolo[1,5-a]pyrimidine-3,5-diamine;3-aminopyrazolo[1,5-a]pyrimidin-7-ol;3-aminopyrazolo-[1,5-a]pyrimidin-5-ol;2-(3-aminopyrazolo[1,5-a]-pyrimidin-7-ylamino)ethanol,2-(7-aminopyrazolo[1,5-a]-pyrimidin-3-ylamino)ethanol,2-((3-aminopyrazolo-[1,5-a]pyrimidin-7-yl)(2-hydroxyethyl)amino]ethanol,2-[(7-aminopyrazolo[1,5-a]pyrimidin-3-yl)(2-hydroxyethyl)amino]ethanol,5,6-dimethylpyrazolo-[1,5-a]pyrimidine-3,7-diamine,2,6-dimethylpyrazolo-[1,5-a]pyrimidine-3,7-diamine,2,5,N7,N7-tetramethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,3-amino-5-methyl-7-imidazolylpropylamino pyrazolo-[1,5-a]pyrimidine,their addition salts with an acid and their tautomeric forms, when atautomeric equilibrium exists.

Among the pyrazole derivatives, mention may be made more particularly ofthe compounds described in Patents DE 3 843 892, DE 4 133 957 and PatentApplications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 195 43 988,such as 4,5-diamino-1-methylpyrazole, 3,4-diaminopyrazole,4,5-diamino-1-(4′-chlorobenzyl)pyrazole,4,5-diamino-1,3-dimethylpyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole,4,5-diamino-1-methyl-3-phenylpyrazole,4-amino-1,3-dimethyl-5-hydrazinopyrazole,1-benzyl-4,5-diamino-3-methylpyrazole,4,5-diamino-3-tert-butyl-1-methylpyrazole,4,5-diamino-1-tert-butyl-3-methylpyrazole,4,5-diamino-1-(β-hydroxyethyl)-3-methylpyrazole,4,5-diamino-1-ethyl-3-methylpyrazole,4,5-diamino-1-ethyl-3-(4′-methoxyphenyl)pyrazole,4,5-diamino-1-ethyl-3-hydroxymethylpyrazole,4,5-diamino-3-hydroxymethyl-1-methylpyrazole,4,5-diamino-3-hydroxymethyl-1-isopropylpyrazole,4,5-diamino-3-methyl-1-isopropylpyrazole,4-amino-5-(2′-aminoethyl)amino-1,3-dimethylpyrazole,3,4,5-triaminopyrazole, 1-methyl-3,4,5-triaminopyrazole,3,5-diamino-1-methyl-4-methylaminopyrazole,3,5-diamino-4-(β-hydroxyethyl)amino-1-methylpyrazole, and their additionsalts with an acid.

When they are used, these additional oxidation bases representpreferably from 0.0005 to 12% by weight, approximately, of the totalweight of the dyeing composition, and more preferably still from 0.005to 6% by weight, approximately, of this weight.

The oxidation dyeing compositions according to the invention may alsoinclude at least one coupler and/or at least one direct dye, inparticular for the purpose of modifying the shades or enriching themwith glints.

The couplers which may be used in the oxidation dyeing compositionsaccording to the invention may be selected from the couplers usedconventionally in oxidation dyeing, among which mention may be made inparticular of meta-phenylenediamines, meta-aminophenols, meta-diphenolsand the heterocyclic couplers such as, for example, the indolederivatives, indoline derivatives, pyridine derivatives and pyrazolones,and their addition salts with an acid.

These couplers are selected more particularly from2-methyl-5-aminophenol, 5-N-(β-hydroxyethyl)amino-2-methylphenol,3-aminophenol, 1,3-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene,4-chloro-1,3-dihydroxybenzene, 2,4-diamino-1-(β-hydroxyethyloxy)benzene,2-amino-4-(β-hydroxyethylamino)-1-methoxybenzene, 1,3-diaminobenzene,1,3-bis (2,4-diaminophenoxy)propane, sesamol, α-naphthol,6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N-methylindole,6-hydroxyindoline, 2,6-dihydroxy-4-methylpyridine,1H-3-methylpyrazol-5-one, 1-phenyl-3-methylpyrazol-5-one, and theiraddition salts with an acid.

When they are present, these couplers represent preferably from 0.0001to 10% by weight, approximately, of the total weight of the dyeingcomposition, and more preferably still from 0.005 to 5% by weight,approximately, of this weight.

Generally speaking, the addition salts with an acid which may be used inthe context of the invention (compounds of formula (I), additionaloxidation bases and couplers) are selected in particular from thehydrochlorides, hydrobromides, sulphates, citrates, succinates,tartrates, lactates and acetates.

The dyeing composition in accordance with the invention may also includevarious adjuvants which are conventionally employed in hair-dyeingcompositions, such as anionic, cationic, nonionic, amphoteric orzwitterionic surfactants or mixtures thereof, anionic, cationic,nonionic, amphoteric or zwitterionic polymers or mixtures thereof,mineral or organic thickeners, antioxidants, penetrants, sequestrants,perfumes, buffers, dispersants, conditioning agents such as, forexample, silicones, film-formers, preservatives and opacifiers.

The person skilled in the art will of course take care to select this orthese optional complementary compounds such that the advantageousproperties intrinsically associated with the oxidation dyeingcomposition in accordance with the invention are not, or notsubstantially, adversely affected by the intended addition or additions.

The dyeing composition according to the invention may be presented in avariety of forms, such as in the form of liquids, creams, gels, or inany other form appropriate for carrying out dyeing of keratinous fibresand, in particular, of human hair.

The invention additionally provides a method of dyeing keratinous fibresand, in particular, human keratinous fibres such as the hair, employingthe dyeing composition as defined above.

In accordance with this method, at least one dyeing composition asdefined above is applied to the fibres, the colour being revealed at anacidic, neutral or alkaline pH with the aid of an oxidizing agent whichis added to the dyeing composition right at the time of use or which ispresent in an oxidizing composition which is applied simultaneously orsequentially, separately.

In accordance with a preferred embodiment of the dyeing method of theinvention, the dyeing composition described above is preferably mixed atthe time of use with an oxidizing composition comprising, in a mediumappropriate for dyeing, at least one oxidizing agent present in anamount sufficient to develop a coloration. The mixture obtained is thenapplied to the keratinous fibres and is left to act for fromapproximately 3 to 50 minutes, preferably for from 64 approximately 5 to30 minutes, after which the fibres are rinsed, washed with shampoo,rinsed again and dried.

The oxidizing agent may be selected from the oxidizing agents which areconventionally used for the oxidation dyeing of keratinous fibres, amongwhich mention may be made of hydrogen peroxide, urea peroxide, alkalimetal bromates, persalts such as perborates and persulphates, andenzymes such as peroxidases, laccases, tyrosinases and oxidoreductases,among which mention may be made in particular of the pyranose oxidases,glucose oxidases, glycerol oxidases, lactate oxidases, pyruvate oxidasesand uricases.

The pH of the oxidizing composition comprising the oxidizing agent asdefined above is such that, after mixing with the dyeing composition,the pH of the resultant composition that is applied to keratinous fibresvaries preferably between approximately 3 and 12, and more preferablystill between 5 and 11. It is adjusted to the desired value by means ofacidifying or basifying agents which are commonly employed in dyeingkeratinous fibres, such agents being as defined above.

The oxidizing composition as defined above may also include variousadjuvants which are conventionally used in hair-dyeing compositions,such adjuvants being as defined above.

The composition which is ultimately applied to the keratinous fibres maybe presented in various forms, such as in the form of liquids, creams orgels or in any other form appropriate for carrying out dyeing ofkeratinous fibres and, in particular, of human hair.

The invention also provides a multi-compartment dyeing device or “kit”,or any other packaging system having two or more compartments, of whicha first compartment contains the dyeing composition as defined above anda second compartment contains the oxidizing composition as definedabove. These devices may be equipped with a means allowing the desiredmixture to be delivered to the hair, such as the devices described inPatent FR-2 586 913 in the name of the applicant.

The examples which follow are intended to illustrate the inventionwithout limiting its scope.

PREPARATION EXAMPLES Preparation Example 1 Synthesis of3-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-(2-hydroxyethyl)-3H-imidazol-1-iumdihydrochloride

A) Preparation of 3-nitro-5-methylpyrazolo[1,5-a]pyrimidin-7-ol

50 g of 4-nitro-2H-pyrazol-3-ylamine hydrochloride (prepared inaccordance with H. Dorn and H. Dilcher, Liebigs Ann. Chem., 707, 141,1967) and 60 g of ethyl acetoacetate in 160 cc of acetic acid wereintroduced into a 500 cc three-necked round-bottomed flask equipped witha magnetic stirrer, a thermometer and a condenser. The reaction mediumwas refluxed for 12 hours. The precipitate which formed was filtered offat about 90° C. It was washed with diisopropyl ether and dried undervacuum over phosphoric anhydride. This gave 50 g of3-nitro-5-methylpyrazolo[1,5-a]pyrimidin-7-ol in the form of yellowcrystals (yield=84.5%; melting point=290° C. with decomposition), whoseelemental analysis, calculated for C₇H₆N₄O₃ (MW=194.15 g), was asfollows:

% C H N O Calculated 43.31 3.12 28.86 24.72 Found 43.12 3.11 28.77 24.65

b) Preparation of 7-chloro-5-methyl-3-nitropyrazolo-[1,5-a]pyrimidine

230 cc of phosphorus oxychloride, 15.4 g of N,N-dimethylaniline and 23.3g of 3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ol were introduced intoa 500 cc three-necked flask equipped with a magnetic stirrer, athermometer and a condenser. The reaction medium was refluxed for 2.5 h.Following evaporation of the phosphorus oxychloride under reducedpressure, a highly viscous green oil was obtained to which approximately400 g of ice were added. A brown solid precipitated. After 30 minutes ofstirring, the precipitate was filtered off and washed with petroleumether and then with diisopropyl ether. Drying under vaccum overphosphoric anhydride gave 21.4 g of7-chloro-5-methyl-3-nitropyrazolo[1,5-a]pyrimidine in the form of abrown solid with a yield of 83.9%.

c) Preparation of(3-imidazol-1-ylpropyl)(5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-7-yl)amine

2.88 g of 3-imidazol-1-ylpropylamine and 2.33 g of triethylamine in 20cc of dioxane were introduced into a 100 cc three-necked round-bottomedflask equipped with a magnetic stirrer, a thermometer, a dropping funneland a condenser. 4.5 g of7-chloro-5-methyl-3-nitropyrazolo[1,5-a]pyrimidine in solution in 20 ccof dioxane and 5 cc of dimethylformamide were added dropwise. After 2hours of stirring at room temperature, the precipitate was filtered off.It was washed with diisopropyl ether and dried under vacuum. This gave7.2 g of crude product. This product was taken up under reflux in 28 ccof water, then filtered off at room temperature. This operation wasrepeated a second time. The product was washed with ethanol and withdiisopropyl ether. This gave 4.1 g of(3-imidazol-1-ylpropyl)(5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-7-yl)aminein the form of a beige powder, after drying under vacuum over phosphoricanhydride, with a yield of 65%.

d) Preparation of1-(2-hydroxyethyl)-3-[3-(5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-3H-imidazol-1-iumchloride

3 g of(3-imidazol-1-ylpropyl)(5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-7-yl)amineand 10 g of 2-chloroethanol were introduced into a 25 cc three-neckedround-bottomed flask equipped with a magnetic stirrer, a thermometer anda condenser. The medium was refluxed for 6 hours. The reaction mediumwas poured into 160 cc of ethyl acetate and refluxed. The precipitatewas filtered off at room temperature. This gave 3.8 g of1-(2-hydroxyethyl)-3-[3-(5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-3H-imidazol-1-iumchloride (beige powder) after drying under vacuum over phosphoricanhydride.

e) Preparation of3-[3-(3-amino-5-methylpyrazolo-[1,5-a]pyrimidin-7-ylamino)propyl]-1-(2-hydroxyethyl)-3H-imidazol-1-iumchloride dihydrochloride

3.5 g of1-(2-hydroxyethyl)-3-[3-(5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-3H-imidazol-1-iumchloride in 150 cc of ethanol and then 0.39 g of 5% palladium on carbon(containing 50% water) were introduced into a 250 cc hydrogenator.Between 11 and 12 bars' pressure of hydrogen were introduced into thereactor and the reaction medium was brought to 60° C. After 4 hours ofreaction, the catalyst was filtered over Celite and a stream of gaseoushydrochloric acid was passed through the filtrate. The reaction mediumwas poured into 100 cc of diisopropyl ether. After stirring, theprecipitate was filtered off. It was washed with diisopropyl ether anddried under vacuum over phosphoric anhydride. This gave 3.3 g of ahighly hygroscopic product. A 3% aqueous solution of this product wasformed, and was lyophilized. The resulting solid was taken up at refluxin 30 cc of absolute ethanol. This gives 2.25 g of3-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimdin-7-ylamino)propyl]-1-(2-hydroxyethyl)-3H-imidazol-1-iumchloride in the form of the dihydrochloride, after drying under vacuumover phosphoric anhydride, with a yield of 85%, whose analysiscalculated for C₁₅H₂₂N₇OCl, 2HCl (MW=424.76 g) was as follows:

% C H N O Cl Calculated 42.42 5.70 23.08 3.77 25.04 Found 40.28 6.1921.40 7.99 24.14 Calculated with 40.69 5.92 22.14 7.23 24.02 1 mol ofwater

Preparation Example 2 Synthesis of3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1-(2-hydroxyethyl)pyridiniumchloride, hydrochloride

a) Preparation of the Methyl Ester of 3-oxo-2-pyridin-3-ylmethylbutyricacid

25 g of the methyl ester of 2-acetyl-3-pyridin-3-ylacrylic acid(prepared in accordance with I. Adachi et al., Chem. Pharm. Bull. 35(8),3235, 1987), 200 cc of ethanol and 5.25 g of 5% palladium on carbon(containing 50% water) were introduced into a 300 cc hydrogenationreactor. A hydrogen pressure of 6 bars was introduced and the reductionwas carried out at ambient temperature. The reaction medium was treatedwhen there was no longer any absorption of hydrogen. The catalyst wasfiltered off and the solvent was evaporated. This gave 24 g of crudeproduct which was treated with 200 cc of diethyl ether. The whiteprecipitate was filtered off and the solvent was evaporated. This gave20 g of the methyl ester of 3-oxo-2-pyridin-3-ylmethylbutyric acid inthe form of a brown oil, with a yield of 79%.

b) Preparation of5-methyl-3-nitro-6-pyridin-3-yl-methylpyrazolo[1,5-a]pyrimidin-7-olhydrochloride

89 g of 4-nitro-2H-pyrazol-3-ylamine (prepared in accordance with H.Dorm and H. Dilcher, Liebigs Ann. Chem., 707, 141, 1967) and 112 g ofthe methyl ester of 3-oxo-2-pyridin-3-ylmethylbutyric acid, obtainedabove in the preceding step, in 1120 cc of acetic acid were introducedinto a 2-liter three-necked round-bottomed flask equipped with amagnetic stirrer, a thermometer and a condenser. The reaction medium wasrefluxed for 5 hours. The precipitate which formed was filtered off atroom temperature. It was rinsed with diisopropyl ether and dried undervacuum over phosphoric anhydride. This gave 120 g of crude product. Thiswas recrystallized from a water/acetone (1/25) mixture. This gave 77 gof 5-methyl-3-nitro-6-pyridin-3-ylmethylpyrazolo[1,5-a]pyrimidin-7-olhydrochloride in the form of yellow crystals (yield=50%), whoseelemental analysis calculated for C₁₃H₁₁N₅O₃.HCl was as follows:

% C H N O Cl Calculated 48.53 3.76 21.77 14.92 11.02 Found 48.31 3.8221.89 14.23 11.75

c) Preparation of5-methyl-3-nitro-6-pyridin-3-yl-methylpyrazolo[1,5-a]pyrimidin-7-ol

250 cc of water and 10.6 g of 20% aqueous ammonia were introduced into a500-cc Erlenmeyer flask equipped with a magnetic stirrer. 20 g of5-methyl-3-nitro-6-pyridin-3-ylmethylpyrazolo[1,5-a]pyrimidin-7-olhydrochloride were added in solid portions. The reaction mixture wasleft with stirring at room temperature for 3 hours. The resulting solidwas filtered off and then washed with 100 cc of water and then withdiisopropyl ether. The product was dried over phosphoric anhydride. Thisgave 16 g of5-methyl-3-nitro-6-pyridin-3-ylmethylpyrazolo[1,5-a]pyrimidin-7-ol witha yield of 90%.

d) Preparation of1-(2-hydroxyethyl)-3-(7-hydroxy-5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-6-ylmethyl)-pyridiniumchloride

10 g of5-methyl-3-nitro-6-pyridin-3-yl-methylpyrazolo[1,5-a]pyrimidin-7-ol,obtained above in the preceding step, and 100 cc of 2-chloroethanol wereintroduced into a 250-cc three-necked round-bottomed flask equipped witha magnetic stirrer, a thermometer and a condenser. The medium wasrefluxed for 5 hours. The solvent was evaporated and then the productwas treated with ethanol. The precipitate was filtered off at roomtemperature. This gave 10 g of crude product. It was recrystallized fromacetic acid. This gave 6.7 g of1-(2-hydroxyethyl)-3-(7-hydroxy-5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-6-ylmethyl)pyridiniumchloride after drying under vacuum over phosphoric anhydride(yield=52%), whose elemental analysis calculated for C₁₅H₁₆N₅O₄.Cl with0.28 mol of acetic acid was as follows:

% C H N O Cl Calculated 48.80 4.47 18.29 19.07 9.28 Found 47.69 4.5618.26 18.85 9.51

e) Preparation of3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1-(2-hydroxyethyl)pyridiniumchloride, hydrochloride

2 g of1-(2-hydroxyethyl)-3-(7-hydroxy-5-methyl-3-nitropyrazolo[1,5-a]pyrimidin-6-ylmethyl)-pyridiniumchloride obtained above in the preceding step in 200 cc of acetic acidand then 0.6 g of 5% palladium on carbon (containing 50% water) wereintroduced into a 500 cc hydrogenator. 8 bars of hydrogen pressure wereintroduced into the reactor and the reaction medium was brought to 50°C. After reaction for 3 hours, the catalyst was filtered off overCelite. The solvent was evaporated and the crude product obtained wastaken up in 10 cc of 7M hydrochloric ethanol. The precipitate wasfiltered off. It was washed with diisopropyl ether and dried undervacuum over phosphoric anhydride. This gave 2.7 g of3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]pyrimidin-6-yl-methyl)-1-(2-hydroxyethyl)pyridiniumchloride (a highly hygroscopic product) in the form of thehydrochloride, after drying under vacuum over phosphoric anhydride, witha yield of 75% and an analysis, calculated for C₁₅H₁₈N₅O₂Cl.HCl, whichwas as follows:

% C H N O Cl Calculated 48.40 5.14 18.81 8.60 19.05 Found 47.04 5.2517.59 10.26 18.40 Calculated 47.20 5.24 18.34 10.48 18.61 with 0.5 molof water

Application Examples Examples 1 to 7 of Dyeing in a Basic Medium

The following dyeing compositions (amounts in grams) were prepared:

EXAMPLE 1 2 3 4 5 6 7 3-[3-(3-Amino-5-methylpyrazolo[1,5-a]- 1.27 1.271.27 1.27 1.27 1.27 1.27 pyrimidin-7-ylamino)propyl]-1-(2-hydroxy-ethyl)-3H-imidazol-1-ium chloride dihydro- chloride (oxidation base offormula (I)) 1,3-Dihydroxybenzene (coupler) — 0.33 — — — — —3-Aminophenol (coupler) — — 0.327 — — — — 5-N-(β-Hydroxyethyl)amino2-methylphenol — — — 0.504 — — — (coupler) 2,4-Diamino1-(β-hydroxyethyloxy)benzene, 2HCl — — — — 0.723 — — (coupler)6-Hydroxyindole (coupler) — — — — — 0.399 — 4-Hydroxyindole (coupler) —— — — — — 0.399 Common dyeing vehicle 1 (*) (*) (*) (*) (*) (*) (*)Demineralized water q.s. 100 g 100 g 100 g 100 g 100 g 100 g 100 g

(*) Common dyeing vehicle 1: 96° ethyl alcohol 18 g Sodiummetabisulphite in 35% aqueous 0.68 g solution Pentasodium salt of 1.1 gdiethylenetriaminepentaacetic acid 20% aqueous ammonia 10.0 g

Each of the above dyeing compositions was mixed at the time of use,weight for weight, with a 20-volume hydrogen peroxide solution (6% byweight) with a pH of 3.

The mixture obtained was applied to locks of permed grey hair containing90% white hair, for 30 minutes. The locks were subsequently rinsed,washed with a standard shampoo, rinsed again and then dried.

The shades obtained are given in the table below:

EXAMPLE Dyeing pH Shade obtained 1 10 ± 0.2 iridescent dark blonde 2 10± 0.2 coppery red 3 10 ± 0.2 purple mahogany 4 10 ± 0.2 red copper 5 10± 0.2 deep violet irridescent light chestnut 6 10 ± 0.2 natural chestnut7 10 ± 0.2 deep red irridescent

Examples 8 to 14 of Dyeing in a Neutral Medium

The following dyeing compositions (amounts in grams) were prepared:

EXAMPLE 8 9 10 11 12 13 14 3-[3-(3-Amino-5-methylpyrazolo[1,5-a]- 1.271.27 1.27 1.27 1.27 1.27 1.27 pyrimidin-7-ylamino)propyl]-1-(2-hydroxy-ethyl)-3H-imidazol-1-ium chloride dihydro- chloride (oxidation base offormula (I)) 1,3-Dihydroxybenzene (coupler) — 0.33 — — — — —3-Aminophenol (coupler) — — 0.327 — — — — 5-N-(β-Hydroxyethyl)amino2-methylphenol — — — 0.504 — — — (coupler) 2,4-Diamino1-(β-hydroxyethyloxy)benzene, 2HCl — — — — 0.723 — — (coupler)6-Hydroxyindole (coupler) — — — — — 0.399 — 4-Hydroxyindole (coupler) —— — — — — 0.399 Common dyeing vehicle 2 (**) (**) (**) (**) (**) (**)(**) Demineralized water q.s. 100 g 100 g 100 g 100 g 100 g 100 g 100 g

(**) Common dyeing vehicle 2: 96° ethanol 18 g K₂HPO₄/KH₂PO₄ (1.5 M/1 M)buffer Sodium metabisulphite 10 g Pentasodium salt of 0.68 gdiethylenetriaminepentaacetic acid

Each of the above dyeing compositions was mixed at the time of use,weight for weight, with a 20-volume hydrogen peroxide solution (6% byweight) with a pH of 3.

The mixture obtained was applied to locks of natural grey haircontaining 90% white hair, for 30 minutes. The locks were subsequentlyrinsed, washed with a standard shampoo, rinsed again and then dried.

The shades obtained are given in the table below:

EXAMPLE Dyeing pH Shade obtained  8 5.7 ± 0.2 coppery iridescent blonde 9 5.7 ± 0.2 beige light ash blonde 10 5.7 ± 0.2 coppery brown darkblonde 11 5.7 ± 0.2 coppery dark blonde 12 5.7 ± 0.2 purplish red 13 5.7± 0.2 natural dark ash blonde 14 5.7 ± 0.2 reddish purple

What is claimed is:
 1. At least one chemical chosen from compounds offormula (I), and acid-addition salt thereof:

in which: R₁, R₂ and R₃, which may be identical or different, are eachchosen from a hydrogen atom; a halogen atom; a group Z; a (C₁-C₆alkyl)carbonyl radical; an amino(C₁-C₆ alkyl)carbonyl radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl radical; an N-(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl radical; an N,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonylradical; an amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; a carboxylradical; a (C₁-C₆ alkyl)carboxyl radical; a (C₁-C₆ alkyl)sulphonylradical; an aminosulphonyl radical; an N-Z-aminosulphonyl radical; anN-(C₁-C₆ alkyl)aminosulphonyl radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl radical; an aminosulphonyl(C₁-C₆ alkyl) radical; anN-Z-aminosulphonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; a carbamyl radical; anN-(C₁-C₆ alkyl)carbamyl radical; an N,N-di(C₁-C₆ alkylcarbamyl radical;a carbamyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl)radical; an N,N-di(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl) radical; a C₁-C₆alkyl radical; a hydroxyl radical; a nitro radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; a C₁-C₆ trifluoroalkyl radical; a cyanoradical; a group OR₆; a group SR₆; an amino radical; an N-(C₁-C₆alkyl)amino radical; an N,N-di(C₁-C₆ alkyl)amino radical, wherein thetwo alkyl substituents may form a ring chosen from 5- and 6-memberedrings; an N-hydroxy(C₁-C₆ alkyl)amino radical; an N,N-bis(hydroxy(C₁-C₆alkyl))amino radical; an N-polyhydroxy(C₂-C₆ alkyl)amino radical; anN,N-bis(polyhydroxy(C₂-C₆ alkyl))amino radical; an amino(C₁-C₆alkyl)amino radical, in which the terminal amino group is unsubstitutedor substituted by one or two C₁-C₆ alkyl radicals, where the alkylradicals may form a ring chosen from saturated and unsaturated 5- and6-membered rings; an amino group protected by at least one group chosenfrom a (C₁-C₆ alkyl)carbonyl, a trifluoro(C₁-C₆ alkyl)carbonyl, anamino(C₁-C₆ alkyl)carbonyl, an N-Z-amino(C₁-C₆ alkyl)carbonyl, anN-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl, an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl radical, an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl) formyl radical, and a group Z; R₆ is chosenfrom a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; a group Z; a C₁-C₆ (C₁-C₆ alkoxy)alkylradical; an aryl radical; a benzyl radical; a C₁-C₆ carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a C₁-C₆ cyanoalkylradical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ trifluoroalkyl radical; a C₁-C₆ aminosulphonylalkylradical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)carbonylalkyl radical; a C₁-C₆ aminoalkyl radical; a C₁-C₆aminoalkyl radical whose amine is substituted by one or two radicalschosen from C₁-C₆ alkyl, monohydroxy(C₁-C₇₆ alkyl), polyhydroxy(C₂-C₆alkyl), (C₁-C₆ alkyl)carbonyl, formyl, trifluoro(C₁-C₆ alkyl)carbonyl,and (C₁-C₆ alkyl)sulphonyl radicals, and a group Z; A is chosen from—NR₄R₅ and a hydroxyl radical; R₄ and R₅, are independently chosen froma hydrogen atom; a group Z; a C₁-C₆ alkyl radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; an aryl radical; a benzyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ thiocarbamylalkyl radical; a C₁-C₆ trifluoroalkylradical; a C₁-C₆ sulphoalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆aminosulphonylalkyl radical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)-aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carbonylalkylradical; a C₁-C₆ aminoalkyl radical; and a C₁-C₆ aminoalkyl radicalwhose amine is substituted by one or two radicals chosen from C₁-C₆alkyl, C₁-C₆ monohydroxyalkyl, C₂-C₆ polyhydroxyalkyl, (C₁-C₆alkyl)carbonyl, (C₁-alkyl)sulphonyl, formyl, and trifluoro(C₁-C₆alkyl)carbonyl radicals, and a group Z; wherein one and only one of theradicals R₄ and R₅ may also be chosen from a (C₁-C₆ alkyl)carbonylradical; a formyl radical; a trifluoro(C₁-C₆ alkyl)carbonyl radical; anamino(C₁-C₆ alkyl)carbonyl radical; an N-Z-amino(C₁-C₆ alkyl)carbonylradical; an N-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; and anN,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; Z is chosen fromthe unsaturated cationic groups of formulae (II) and (III) below and thesaturated cationic groups of formula (IV) below:

in which: D is a linker which is chosen from linear and branched alkylchains and may be interrupted by at least one heteroatom atom and may besubstituted by at least one of a hydroxyl and a C₁-C₆ alkoxy radical,and may carry at least one ketone function; the ring members E, G, J, Land M, which are identical or different, are chosen from carbon, oxygen,sulphur and nitrogen atoms; n is an integer ranging from 0 to 4; m is aninteger ranging from 0 to 5; the radicals R, which are identical ordifferent, may be chosen from a group Z; a halogen atom; a hydroxylradical; a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; aC₂-C₆ polyhydroxyalkyl radical; a nitro radical; a cyano radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxy radical; a C₁-C₆ tri(C₁-C₆alkyl)silanealkyl radical; an amido radical; an aldehydo radical; acarboxyl radical; a C₁-C₆ alkylcarbonyl radical; a thio radical; a C₁-C₆thioalkyl radical; a (C₁-C₆ alkyl)thio radical; an amino radical; anamino radical protected by a group chosen from (C₁-C₆ alkyl)carbonyl,carbamyl, and (C₁-C₆ alkyl)sulphonyl; and groups NHR″ and NR″R′″ inwhich R′ and R′″, which are identical or different, are chosen from aC₁-C₆ alkyl radical, a C₁-C₆ monohydroxyalkyl radical and a C₂-C₆polyhydroxyalkyl radical; R₇ is chosen from a C₁-C₆ alkyl radical; aC₁-C₆ monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a carbamyl(C₁-C₆ alkyl) radical; aC₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a benzyl radical; and a groupZ; R₈, R₉ and R₁₀, which are identical or different, are chosen from aC₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; a C₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a C₁-C₆cyanoalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆amidoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; and aC₁-C₆ aminoalkyl radical whose amine is protected by at least one of a(C₁-C₆ alkyl)carbonyl, amido, carboxyl and (C₁-C₆ alkyl)sulphonylradical; two of the radicals R₈, R₉ and R₁₀ may form, together with thenitrogen to which they are attached, a ring chosen from saturated 5- and6-membered carbon-containing rings which may contain at least oneheteroatom, wherein said rings may contain a substituent chosen from ahalogen atom; a hydroxyl radical; a C₁-C₆ alkyl radical, a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a nitroradical; a cyano radical; a C₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxyradical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; an amido radical;an aldehydo radical; a carboxyl radical; a C₁-C₆ ketoalkyl radical; athio radical; a C₁-C₆ thioalkyl radical; a (C₁-C₆ alkyl)thio radical; anamino radical; and an amino radical protected by a group chosen from(C₁-C₆ alkyl)carbonyl; carbamyl and (C₁-C₆ alkyl)sulphonyl radical; oneof the radicals R₈, R₉ and R₁₀ may be chosen from a second group Z,identical to or different from the first group Z; R₁₁ may be chosen froma C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆aminoalkyl radical; a C₁-C₆ aminoalkyl radical whose amine is protectedby at least one of a (C₁-C₆ alkyl)carbonyl, a carbamyl, and a (C₁-C₆alkyl)sulphonyl radical; a C₁-C₆ carboxyalkyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆trifluoroalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ sulphonamidoalkyl radical; a C₁-C₆(C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆(C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)ketoalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)carbamylalkyl radical; and a C₁-C₆ N-(C₁-C₆alkyl)sulphonamidoalkyl radical; a and y are integers equal to 0 or 1;with the following conditions: in the unsaturated cationic groups offormula (II): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J orL, y can adopt the value 1 only 1) when the ring members E, G, J and Lare simultaneously a carbon atom and when the radical R₇ is carried bythe nitrogen atom of the unsaturated ring; or 2) when at least one ofthe ring members E, G, J and L is chosen from a nitrogen atom to whichthe radical R₇ is attached; in the unsaturated cationic groups offormula (III): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J, Lor M, y can adopt the value 1 only 1) when at least one of the ringmembers E, G, J, L and M is chosen from a divalent atom and 2) when theradical R₇ is carried by the nitrogen atom of the unsaturated ring; inthe saturated cationic groups of formula (IV): when a=0, then the linkerD is attached to the nitrogen atom which carries the radicals R₈ to R₁₀,when a=1, then two of the radicals R₈ to R₁₀, together with the nitrogenatom to which they are attached, form a ring chosen from 5- and6-membered saturated rings, and the linker D is carried by a carbon atomof the said ring; X⁻ is chosen from monovalent and divalent anions; withthe proviso that at least one of R₁, R₂ and R₃ is a group Z.
 2. At leastone chemical according to claim 1, wherein in said formulas (II), (III),and (IV), D is chosen from linear and branched alkyl chains having from1 to 14 carbon atoms.
 3. At least one chemical according to claim 2,wherein said alkyl chains are interrupted by at least one heteroatomchosen from oxygen, sulphur, and nitrogen atoms.
 4. At least onechemical according to claim 1, wherein the rings of the unsaturatedgroup Z of formula (II) are chosen from pyrrole, imidazole, pyrazole,oxazole, thiazole and triazole rings.
 5. At least one chemical accordingto claim 1, wherein the rings of the unsaturated group Z of formula(III) are chosen from pyridine, pyrimidine, pyrazine, oxazine andtriazine rings.
 6. At least one chemical according to claim 1, whereintwo of the radicals R₈, R₉ and R₁₀ in said saturated group Z of formula(IV) form a ring chosen from a pyrrolidine ring, a piperidine ring, apiperazine ring and a morpholine ring.
 7. At least one chemicalaccording to claim 1, wherein X⁻ is chosen from a halogen atom, ahydroxide, a hydrogen sulphate and a C₁-C₆ alkyl sulphate.
 8. At leastone chemical according to claim 1 chosen from:3-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-(2-hydroxyethyl)-3H-imidazol-1-iumchloride,3-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylcarbamoyl)methyl]-1-methyl-3H-imidazol-1-iumchloride,3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1-methylpyridiniummethyl sulphate,3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1-(2-hydroxyethyl)pyridiniumchloride,2-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)methyl]-1,3-dimethyl-3H-imidazol-1-iummethyl sulphate,3-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)methyl]-1-methylpyridiniummethyl sulphate,3-[(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)methyl]-1-methylpyridiniummethyl sulphate,2-(3,7-diamino-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1,3-dimethyl3H-imidazol-1-iummethyl sulphate,2-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1,3-dimethyl-3H-imidazol-1-iummethyl sulphate,2-(3,7-diaminopyrazolo[1,5-a]pyrimidin-2-yl)-1-methylpyridinium methylsulphate,[3-(3-amino-5-methlpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]trimethylammoniumchloride,[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]trimethylammoniummethyl sulphate,1-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-methylpiperidiniumchloride,1-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-methylpiperdiniummethyl sulphate, 4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]4-methylmorpholin-4-iumchloride, 4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]4-methylmorpholin-4-ium methylsulphate, and the acid-addition salts thereof.
 9. At least one chemicalaccording to claim 8 chosen from:3-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-1-(2-hydroxyethyl)-3H-imidazol-1-iumchloride, 3-(3-amino-7-hydroxy-5methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1-methylpyridinium methyl sulphate,3-(3-amino-7-hydroxy-5-methylpyrazolo[1,5-a]pyrimidin-6-ylmethyl)-1-(2-hydroxyethyl)pyridiniumchloride, 4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-4-methylmorpholin-4-iumchloride, 4-[3-(3-amino-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)propyl]-4-methylmorpholin-4-iummethyl sulphate, and the acid-addition salts thereof.
 10. At least onechemical according to claim 1, wherein said acid-addition salts arechosen from hydrochlorides, hydrobromides, sulphates, citrates,succinates, tartrates, lactates and acetates.
 11. At least one chemicalaccording to claim 8, wherein said acid-addition salts are chosen fromhydrochlorides, hydrobromides, sulphates, citrates, succinates,tartrates, lactates and acetates.
 12. At least one chemical according toclaim 9, wherein said acid-addition salts are chosen fromhydrochlorides, hydrobromides, sulphates, citrates, succinates,tartrates, lactates and acetates.
 13. A composition for the oxidationdyeing of keratinous fibers, comprising, in a medium suitable fordyeing, at least one oxidation base chosen from compounds of formula (I)and acid addition salts thereof:

in which: R₁, R₂ and R₃, which may be identical or different, are eachchosen from a hydrogen atom; a halogen atom; a group Z; a (C₁-C₆alkyl)carbonyl radical; an amino(C₁-C₆ alkyl)carbonyl radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl radical; an N-(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl radical; an N,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonylradical; an amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; a carboxylradical; a (C₁-C₆ alkyl)carboxyl radical; a (C₁-C₆ alkyl)sulphonylradical; an aminosulphonyl radical; an N-Z-aminosulphonyl radical; anN-(C₁-C₆ alkyl)aminosulphonyl radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl radical; an aminosulphonyl(C₁-C₆ alkyl) radical; anN-Z-aminosulphonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; a carbamyl radical; anN-(C₁-C₆ alkyl)carbamyl radical; an N,N-di(C₁-C₆ alkyl)carbamyl radical;a carbamyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl)radical; an N,N-di(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl) radical; a C₁-C₆alkyl radical; a hydroxyl radical; a nitro radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; a C₁-C₆ trifluoroalkyl radical; a cyanoradical; a group OR₆; a group SR₆; an amino radical; an N-(C₁-C₆alkyl)amino radical; an N,N-di(C₁-C₆ alkyl)amino radical, wherein thetwo alkyl substituents may form a ring chosen from 5-and 6-memberedrings; an N-hydroxy(C₁-C₆ alkyl)amino radical; an N,N-bis(hydroxy(C₁-C₆alkyl))amino radical; an N-polyhydroxy(C₂-C₆ alkyl)amino radical; anbis(polyhydroxy(C₂-C₆ alkyl))amino radical; an amino(C₁-C₆ alkyl)aminoradical, in which the terminal amino group is unsubstituted orsubstituted by one or two C₁-C₆ alkyl radicals, where the alkyl radicalsmay form a ring chosen from saturated and unsaturated 5- and 6-memberedrings; an amino group protected by at least one group chosen from a(C₁-C₆ alkyl)carbonyl, a trifluoro(C₁-C₆ alkyl)carbonyl, an amino(C₁-C₆alkyl)carbonyl, an N-Z-amino(C₁-C₆ alkyl)carbonyl, an N-(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl, an N,N-di(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl radical, an N,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl) formylradical, and a group Z; R₆ is chosen from a C₁-C₆ alkyl radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a group Z; aC₁-C₆ (C₁-C₆ alkoxy)alkyl radical; an aryl radical; a benzyl radical; aC₁-C₆ carboxyalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆N-(C₁-C₆ alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ trifluoroalkyl radical; a C₁-C₆aminosulphonylalkyl radical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)carbonylalkyl radical; a C₁-C₆ aminoalkyl radical; a C₁-C₆aminoalkyl radical whose amine is substituted by one or two radicalschosen from C₁-C₆ alkyl, monohydroxy(C₁-C₆ alkyl), polyhydroxy(C₂-C₆alkyl), (C₁-C₆ alkyl)carbonyl, formyl, trifluoro(C₁-C₆ alkyl)carbonyl,and (C₁-C₆ alkyl)sulphonyl radicals, and a group Z; A is chosen from—NR₄R₅ and a hydroxyl radical; R₄ and R₅, are independently chosen froma hydrogen atom; a group Z; a C₁-C₆ alkyl radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; an aryl radical; a benzyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ thiocarbamylalkyl radical; a C₁-C₆ trifluoroalkylradical; a C₁-C₆ sulphoalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆aminosulphonylalkyl radical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; aC₁-C₆ N-(C₁-C₆ alkylyaminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carbonylalkylradical; a C₁-C₆ aminoalkyl radical; and a C₁-C₆ aminoalkyl radicalwhose amine is substituted by one or two radicals chosen from C₁-C₆alkyl, C₁-C₆ monohydroxyalkyl, C₂-C₆ polyhydroxyalkyl, (C₁-C₆alkyl)carbonyl, (C₁-alkyl)sulphonyl, formyl, and trifluoro(C₁-C₆alkyl)carbonyl radicals, and a group Z; wherein one and only one of theradicals R₄ and R₅ may also be chosen from a (C₁-C₆ alkyl)carbonylradical; a formyl radical; a trifluoro(C₁-C₆ alkyl)carbonyl radical; anamino(C₁-C₆ alkyl)carbonyl radical; an N-Z-amino(C₁-C₆ alkyl)carbonylradical; an N-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; and anN,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; Z is chosen fromthe unsaturated cationic groups of formulae (II) and (III) below and thesaturated cationic groups of formula (IV) below:

in which: D is a linker which is chosen from linear and branched alkylchains and may be interrupted by at least one heteroatom atom and may besubstituted by at least one of a hydroxyl and a C₁-C₆ alkoxy radical,and may carry at least one ketone function; the ring members E, G, J, Land M, which are identical or different, are chosen from carbon, oxygen,sulphur and nitrogen atoms; n is an integer ranging from 0 to 4; m is aninteger ranging from 0 to 5; the radicals R, which are identical ordifferent, may be chosen from a group Z; a halogen atom; a hydroxylradical; a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; aC₂-C₆ polyhydroxyalkyl radical; a nitro radical; a cyano radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxy radical; a C₁-C₆ tri(C₁-C₆alkyl)silanealkyl radical; an amido radical; an aldehydo radical; acarboxyl radical; a C₁-C₆ alkylcarbonyl radical; a thio radical; a C₁-C₆thioalkyl radical; a (C₁-C₆ alkyl)thio radical; an amino radical; anamino radical protected by a group chosen from (C₁-C₆ alkyl)carbonyl,carbamyl, and (C₁-C₆ alkyl)sulphonyl; and groups NHR″ and NR″R′″ inwhich R″ and R′″, which are identical or different, are chosen from aC₁-C₆ alkyl radical, a C₁-C₆ monohydroxyalkyl radical and a C₂-C₆polyhydroxyalkyl radical; R₇ is chosen from a C₁-C₆ alkyl radical; aC₁-C₆ monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a carbamyl(C₁-C₆ alkyl) radical; aC₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a benzyl radical; and a groupZ; R₈, R₉ and R₁₀, which are identical or different, are chosen from aC₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; a C₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a C₁-C₆cyanoalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆amidoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; and aC₁-C₆ aminoalkyl radical whose amine is protected by at least one of a(C₁-C₆ alkyl)carbonyl, amido, carboxyl and (C₁-C₆ alkyl)sulphonylradical; two of the radicals R₈, R₉ and R₁₀ may form, together with thenitrogen to which they are attached, a ring chosen from saturated 5- and6-membered carbon-containing rings which may contain at least oneheteroatom, wherein said rings may contain a substituent chosen from ahalogen atom; a hydroxyl radical; a C₁-C₆ alkyl radical, a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a nitroradical; a cyano radical; a C₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxyradical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; an amido radical;an aldehydo radical; a carboxyl radical; a C₁-C₆ ketoalkyl radical; athio radical; a C₁-C₆ thioalkyl radical; a (C₁-C₆ alkyl)thio radical; anamino radical; and an amino radical protected by a group chosen from(C₁-C₆ alkyl)carbonyl; carbamyl and (C₁-C₆ alkyl)sulphonyl radical; oneof the radicals R₈, R₉ and R₁₀ may be chosen from a second group Z,identical to or different from the first group Z; R₁₁ may be chosen froma C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆aminoalkyl radical; a C₁-C₆ aminoalkyl radical whose amine is protectedby at least one of a (C₁-C₆ alkyl)carbonyl, a carbamyl, and a (C₁-C₆alkyl)sulphonyl radical; a C₁-C₆ carboxyalkyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆trifluoroalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ sulphonamidoalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)ketoalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)carbamylalkyl radical; and a C₁-C₆ N-(C₁-C₆alkyl)sulphonamidoalkyl radical; a and y are integers equal to 0 or 1;with the following conditions: in the unsaturated cationic groups offormula (II): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J orL, y can adopt the value 1 only 1) when the ring members E, G, J and Lare simultaneously a carbon atom and when the radical R₇ is carried bythe nitrogen atom of the unsaturated ring; or 2) when at least one ofthe ring members E, G, J and L is chosen from a nitrogen atom to whichthe radical R₇ is attached; in the unsaturated cationic groups offormula (III): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J, Lor M, y can adopt the value 1 only 1) when at least one of the ringmembers E, G, J, L and M is chosen from a divalent atom and 2) when theradical R₇ is carried by the nitrogen atom of the unsaturated ring; inthe saturated cationic groups of formula (IV): when a=0, then the linkerD is attached to the nitrogen atom which carries the radicals R₈ to R₁₀,when a=1, then two of the radicals R₈ to R₁₀, together with the nitrogenatom to which they are attached, form a ring chosen from 5- and6-membered saturated rings, and the linker D is carried by a carbon atomof the said ring; X⁻ is chosen from monovalent and divalent anions; withthe proviso that at least one of R₁, R₂ and R₃ is a group Z.
 14. Acomposition according to claim 13, wherein in said formulas (II), (III),and (IV), D is chosen from linear and branched alkyl chains having from1 to 14 carbon atoms.
 15. A composition according to claim 13, whereinsaid alkyl chains are interrupted by at least one heteroatom chosen fromoxygen, sulphur, and nitrogen atoms.
 16. A composition according toclaim 13, wherein the rings of the unsaturated group Z of formula (II)are chosen from pyrrole, imidazole, pyrazole, oxazole, thiazole andtriazole rings.
 17. A composition according to claim 13, wherein therings of the unsaturated group Z of formula (III) are chosen frompyridine, pyrimidine, pyrazine, oxazine and triazine rings.
 18. Acomposition according to claim 13, wherein two of the radicals R₈, R₉and R₁₀ in said saturated group Z of formula (IV) form a ring chosenfrom a pyrrolidine ring, a piperidine ring, a piperazine ring and amorpholine ring.
 19. A composition according to claim 13, wherein X⁻ ischosen from a halogen atom, a hydroxide, a hydrogen sulphate and a C₁-C₆alkyl sulphate.
 20. A composition according to claim 13, wherein said atleast one compound of formula (I) is present in said composition in anamount ranging from 0.0005 to 12% by weight relative to the total weightof the composition.
 21. A composition according to claim 20, whereinsaid at least one compound of formula (I) is present in said compositionin an amount ranging from 0.005 to 6% by weight relative to the totalweight of the dyeing composition.
 22. A composition according to claim13, further comprising at least one additional oxidation base chosenfrom para-phenylenediamines, bisphenylalkylenediamines,para-aminophenols, ortho-aminophenols and heterocyclic bases other thanthe compounds of formula (I).
 23. A composition according to claim 22,wherein the at least one additional oxidation base is present in saidcomposition in an amount ranging from 0.0005 to 12% by weight relativeto the total weight of the dyeing composition.
 24. A compositionaccording to claim 13, further comprising at least one of couplers anddirect dyes.
 25. A composition according to claim 24, wherein saidcouplers are chosen from meta-phenylenediamines, meta-aminophenols andmetadiphenols and heterocyclic couplers, and the acid-addition saltsthereof.
 26. A composition according to claim 25, wherein said couplersare chosen from 2-methyl-5-aminophenol,5-N-(β-hydroxyethyl)amino-2-methylphenol, 3-aminophenol,1,3-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene,4-chloro-1,3-dihydroxybenzene, 2,4-diamino-1-(β-hydroxyethyloxy)benzene,2-amino-4-(β-hydroxyethylamino)-1-methoxybenzene, 1,3-diaminobenzene,1,3-bis(2,4-diaminophenoxy)propane, sesamol, α-naphthol,6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N-methylindole,6-hydroxyindoline, 2,6-dihydroxy-4-methylpyridine,1H-3-methylpyrazol-5-one, 1-phenyl-3-methylpyrazol-5-one, and theacid-addition salts thereof.
 27. A composition according to claim 24,wherein at least one coupler is present in said composition in an amountranging from 0.0001 to 10% by weight relative to the total weight of thecomposition.
 28. A composition according to claim 25, wherein theacid-addition salts are chosen from the hydrochlorides, hydrobromides,sulphates, citrates, succinates, tartrates, lactates and acetates.
 29. Acomposition according to claim 26, wherein the acid-addition salts arechosen from the hydrochlorides, hydrobromides, sulphates, citrates,succinates, tartrates, lactates and acetates.
 30. A method for dyeingkeratinous fibers comprising applying a dyeing composition to saidkeratinous fibers, and developing color with the aid of at least oneoxidizing agent, wherein said at least one oxidizing agent is added tothe dyeing composition at the time of application or which is present inan oxidizing composition which is applied simultaneously with saiddyeing composition, either sequentially or separately, wherein saiddyeing composition comprises, in a medium suitable for dyeing, at leastone oxidation base chosen from compounds of formula (I) and acidaddition salts thereof:

in which: R₁, R₂ and R₃, which may be identical or different, are eachchosen from a hydrogen atom; a halogen atom; a group Z; a (C₁-C₆alkyl)carbonyl radical; an amino(C₁-C₆ alkyl)carbonyl radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl radical; an N-(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl radical; an N,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonylradical; an amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; a carboxylradical; a (C₁-C₆ alkyl)carboxyl radical; a (C₁-C₆ alkyl)sulphonylradical; an aminosulphonyl radical; an N-Z-aminosulphonyl radical; anN-(C₁-C₆ alkyl)aminosulphonyl radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl radical; an aminosulphonyl(C₁-C₆ alkyl) radical; anN-Z-aminosulphonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; a carbamyl radical; anN-(C₁-C₆ alkyl)carbamyl radical; an N,N-di(C₁-C₆ alkyl)carbamyl radical;a carbamyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl)radical; an N,N-di(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl) radical; a C₁-C₆alkyl radical; a hydroxyl radical; a nitro radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; a C₁-C₆ trifluoroalkyl radical; a cyanoradical; a group OR₆; a group SR₆; an amino radical; an N-(C₁-C₆alkyl)amino radical; an N,N-di(C₁-C₆ alkyl)amino radical, wherein thetwo alkyl substituents may form a ring chosen from 5- and 6-memberedrings; an N-hydroxy(C₁-C₆ alkyl)amino radical; an N,N-bis(hydroxy(C₁-C₆alkyl))amino radical; an N-polyhydroxy(C₂-C₆ alkyl)amino radical; anN,N-bis(polyhydroxy(C₂-C₆ alkyl))amino radical; an amino(C₁-C₆alkyl)amino radical, in which the terminal amino group is unsubstitutedor substituted by one or two C₁-C₆ alkyl radicals, where the alkylradicals may form a ring chosen from saturated and unsaturated 5- and6-membered rings; an amino group protected by at least one group chosenfrom a (C₁-C₆ alkyl)carbonyl, a trifluoro(C₁-C₆ alkyl)carbonyl, anamino(C₁-C₆ alkyl)carbonyl, an N-Z-amino(C₁-C₆ alkyl)carbonyl, anN-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl, an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl radical, an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl) formyl radical, and a group Z; R₆ is chosenfrom a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; a group Z; a C₁-C₆ (C₁-C₆ alkoxy)alkylradical; an aryl radical; a benzyl radical; a C₁-C₆ carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a C₁-C₆ cyanoalkylradical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ trifluoroalkyl radical; a C₁-C₆ aminosulphonylalkylradical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)carbonylalkyl radical; a C₁-C₆ aminoalkyl radical; a C₁-C₆aminoalkyl radical whose amine is substituted by one or two radicalschosen from C₁-C₆ alkyl, monohydroxy(C₁-C₆ alkyl), polyhydroxy(C₂-C₆alkyl), (C₁-C₆ alkyl)carbonyl, formyl, trifluoro(C₁-C₆ alkyl)carbonyl,and (C₁-C₆ alkyl)sulphonyl radicals, and a group Z; A is chosen from—NR₄R₅ and a hydroxyl radical; R₄ and R₅, are independently chosen froma hydrogen atom; a group Z; a C₁-C₆ alkyl radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; an aryl radical; a benzyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ thiocarbamylalkyl radical; a C₁-C₆ trifluoroalkylradical; a C₁-C₆ sulphoalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆aminosulphonylalkyl radical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)-aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carbonylalkylradical; a C₁-C₆ aminoalkyl radical; and a C₁-C₆ aminoalkyl radicalwhose amine is substituted by one or two radicals chosen from C₁-C₆alkyl, C₁-C₆ monohydroxyalkyl, C₂-C₆ polyhydroxyalkyl, (C₁-C₆alkyl)carbonyl, (C₁-alkyl)sulphonyl, formyl, and trifluoro(C₁-C₆alkyl)carbonyl radicals, and a group Z; wherein one and only one of theradicals R₄ and R₅ may also be chosen from a (C₁-C₆ alkyl)carbonylradical; a formyl radical; a trifluoro(C₁-C₆ alkyl)carbonyl radical; anamino(C₁-C₆ alkyl)carbonyl radical; an N-Z-amino(C₁-C₆ alkyl)carbonylradical; an N-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; and anN,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; Z is chosen fromthe unsaturated cationic groups of formulae (II) and (III) below and thesaturated cationic groups of formula (IV) below:

in which: D is a linker which is chosen from linear and branched alkylchains and may be interrupted by at least one heteroatom atom and may besubstituted by at least one of a hydroxyl and a C₁-C₆ alkoxy radical,and may carry at least one ketone function; the ring members E, G, J, Land M, which are identical or different, are chosen from carbon, oxygen,sulphur and nitrogen atoms; n is an integer ranging from 0 to 4; m is aninteger ranging from 0 to 5; the radicals R, which are identical ordifferent, may be chosen from a group Z; a halogen atom; a hydroxylradical; a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; aC₂-C₆ polyhydroxyalkyl radical; a nitro radical; a cyano radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxy radical; a C₁-C₆ tri(C₁-C₆alkyl)silanealkyl radical; an amido radical; an aldehydo radical; acarboxyl radical; a C₁-C₆ alkylcarbonyl radical; a thio radical; a C₁-C₆thioalkyl radical; a (C₁-C₆ alkyl)thio radical; an amino radical; anamino radical protected by a group chosen from (C₁-C₆ alkyl)carbonyl,carbamyl, and (C₁-C₆ alkyl)sulphonyl; and groups NHR″ and NR″R′″ inwhich R″ and R′″, which are identical or different, are chosen from aC₁-C₆ alkyl radical, a C₁-C₆ monohydroxyalkyl radical and a C₂-C₆polyhydroxyalkyl radical; R₇ is chosen from a C₁-C₆ alkyl radical; aC₁-C₆ monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a carbamyl(C₁-C₆ alkyl) radical; aC₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a benzyl radical; and a groupZ; R₈, R₉ and R₁₀, which are identical or different, are chosen from aC₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; a C₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a C₁-C₆cyanoalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆amidoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; and aC₁-C₆ aminoalkyl radical whose amine is protected by at least one of a(C₁-C₆ alkyl)carbonyl, amido, carboxyl and (C₁-C₆ alkyl)sulphonylradical; two of the radicals R₈, R₉ and R₁₀ may form, together with thenitrogen to which they are attached, a ring chosen from saturated 5- and6-membered carbon-containing rings which may contain at least oneheteroatom, wherein said rings may contain a substituent chosen from ahalogen atom; a hydroxyl radical; a C₁-C₆ alkyl radical, a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a nitroradical; a cyano radical; a C₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxyradical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; an amido radical;an aldehydo radical; a carboxyl radical; a C₁-C₆ ketoalkyl radical; athio radical; a C₁-C₆ thioalkyl radical; a (C₁-C₆ alkyl)thio radical; anamino radical; and an amino radical protected by a group chosen from(C₁-C₆ alkyl)carbonyl; carbamyl and (C₁-C₆ alkyl)sulphonyl radical; oneof the radicals R₈, R₉ and R₁₀ may be chosen from a second group Z,identical to or different from the first group Z; R₁₁ may be chosen froma C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆aminoalkyl radical; a C₁-C₆ aminoalkyl radical whose amine is protectedby at least one of a (C₁-C₆ alkyl)carbonyl, a carbamyl, and a (C₁-C₆alkyl)sulphonyl radical; a C₁-C₆ carboxyalkyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆trifluoroalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ sulphonamidoalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)ketoalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)carbamylalkyl radical; and a C₁-C₆ N-(C₁-C₆alkyl)sulphonamidoalkyl radical; a and y are integers equal to 0 or 1;with the following conditions: in the unsaturated cationic groups offormula (II): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J orL, y can adopt the value 1 only 1) when the ring members E, G, J and Lare simultaneously a carbon atom and when the radical R₇ is carried bythe nitrogen atom of the unsaturated ring; or 2) when at least one ofthe ring members E, G, J and L is chosen from a nitrogen atom to whichthe radical R₇ is attached; in the unsaturated cationic groups offormula (III): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J, Lor M, y can adopt the value 1 only 1) when at least one of the ringmembers E, G, J, L and M is chosen from a divalent atom and 2) when theradical R₇ is carried by the nitrogen atom of the unsaturated ring; inthe saturated cationic groups of formula (IV): when a=0, then the linkerD is attached to the nitrogen atom which carries the radicals R₈ to R₁₀,when a=1, then two of the radicals R₈ to R₁₀, together with the nitrogenatom to which they are attached, form a ring chosen from 5- and6-membered saturated rings, and the linker D is carried by a carbon atomof the said ring; X⁻ is chosen from monovalent and divalent anions; withthe proviso that at least one of R₁, R₂ and R₃ is a group Z.
 31. Themethod according to claim 30, wherein the at least one oxidizing agentis chosen from hydrogen peroxide, urea peroxide, alkali metal bromates,persalts and enzymes.
 32. The method of claim 30, wherein saidkeratinous fibers are hair.
 33. A multi-compartment dyeing kitcomprising at least two compartments, wherein a first compartmentcontains a dyeing composition and a second compartment contains anoxidizing composition, wherein said dyeing composition comprises, in amedium suitable for dyeing, at least one oxidation base chosen fromcompounds of formula (I) and acid addition salts thereof:

in which: R₁, R₂ and R₃, which may be identical or different, are eachchosen from a hydrogen atom; a halogen atom; a group Z; a (C₁-C₆alkyl)carbonyl radical; an amino(C₁-C₆ alkyl)carbonyl radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl radical; an N-(C₁-C₆ alkyl)amino(C₁-C₆alkyl)carbonyl radical; an N,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonylradical; an amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; anN-Z-amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl(C₁-C₆ alkyl) radical; a carboxylradical; a (C₁-C₆ alkyl)carboxyl radical; a (C₁-C₆ alkyl)sulphonylradical; an aminosulphonyl radical; an N-Z-aminosulphonyl radical; anN-(C₁-C₆ alkyl)aminosulphonyl radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl radical; an aminosulphonyl(C₁-C₆ alkyl) radical; anN-Z-aminosulphonyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; an N,N-di(C₁-C₆alkyl)aminosulphonyl(C₁-C₆ alkyl) radical; a carbamyl radical; anN-(C₁-C₆ alkyl)carbamyl radical; an N,N-di(C₁-C₆ alkyl)carbamyl radical;a carbamyl(C₁-C₆ alkyl) radical; an N-(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl)radical; an N,N-di(C₁-C₆ alkyl)carbamyl(C₁-C₆ alkyl) radical; a C₁-C₆alkyl radical; a hydroxyl radical; a nitro radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; a C₁-C₆ trifluoroalkyl radical; a cyanoradical; a group OR₆; a group SR₆; an amino radical; an N-(C₁-C₆alkyl)amino radical; an N,N-di(C₁-C₆ alkyl)amino radical, wherein thetwo alkyl substituents may form a ring chosen from 5- and 6-memberedrings; an N-hydroxy(C₁-C₆ alkyl)amino radical; an N,N-bis(hydroxy(C₁-C₆alkyl))amino radical; an N-polyhydroxy(C₂-C₆ alkyl)amino radical; anN,N-bis(polyhydroxy(C₂-C₆ alkyl))amino radical; an amino(C₁-C₆alkyl)amino radical, in which the terminal amino group is unsubstitutedor substituted by one or two C₁-C₆ alkyl radicals, where the alkylradicals may form a ring chosen from saturated and unsaturated 5- and6-membered rings; an amino group protected by at least one group chosenfrom a (C₁-C₆ alkyl)carbonyl, a trifluoro(C₁-C₆ alkyl)carbonyl, anamino(C₁-C₆ alkyl)carbonyl, an N-Z-amino(C₁-C₆ alkyl)carbonyl, anN-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl, an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl)carbonyl radical, an N,N-di(C₁-C₆alkyl)amino(C₁-C₆ alkyl) formyl radical, and a group Z; R₆ is chosenfrom a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; a group Z; a C₁-C₆ (C₁-C₆ alkoxy)alkylradical; an aryl radical; a benzyl radical; a C₁-C₆ carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a C₁-C₆ cyanoalkylradical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ trifluoroalkyl radical; a C₁-C₆ aminosulphonylalkylradical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)carbonylalkyl radical; a C₁-C₆ aminoalkyl radical; a C₁-C₆aminoalkyl radical whose amine is substituted by one or two radicalschosen from C₁-C₆ alkyl, monohydroxy(C₁-C₆ alkyl), polyhydroxy(C₂-C₆alkyl), (C₁-C₆ alkyl)carbonyl, formyl, trifluoro(C₁-C₆ alkyl)carbonyl,and (C₁-C₆ alkyl)sulphonyl radicals, and a group Z; A is chosen from—NR₄R₅ and a hydroxyl radical; R₄ and R₅, are independently chosen froma hydrogen atom; a group Z; a C₁-C₆ alkyl radical; a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a C₁-C₆(C₁-C₆ alkoxy)alkyl radical; an aryl radical; a benzyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆ N-(C₁-C₆alkyl)carbamylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆ alkyl)carbamylalkylradical; a C₁-C₆ thiocarbamylalkyl radical; a C₁-C₆ trifluoroalkylradical; a C₁-C₆ sulphoalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆aminosulphonylalkyl radical; a C₁-C₆ N-Z-aminosulphonylalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)-aminosulphonylalkyl radical; a C₁-C₆ N,N-di(C₁-C₆alkyl)aminosulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)carbonylalkylradical; a C₁-C₆ aminoalkyl radical; and a C₁-C₆ aminoalkyl radicalwhose amine is substituted by one or two radicals chosen from C₁-C₆alkyl, C₁-C₆ monohydroxyalkyl, C₂-C₆ polyhydroxyalkyl, (C₁-C₆alkyl)carbonyl, (C₁-alkyl)sulphonyl, formyl, and trifluoro(C₁-C₆alkyl)carbonyl radicals, and a group Z; wherein one and only one of theradicals R₄ and R₅ may also be chosen from a (C₁-C₆ alkyl)carbonylradical; a formyl radical; a trifluoro(C₁-C₆ alkyl)carbonyl radical; anamino(C₁-C₆ alkyl)carbonyl radical; an N-Z-amino(C₁-C₆ alkyl)carbonylradical; an N-(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; and anN,N-di(C₁-C₆ alkyl)amino(C₁-C₆ alkyl)carbonyl radical; Z is chosen fromthe unsaturated cationic groups of formulae (II) and (III) below and thesaturated cationic groups of formula (IV) below:

in which: D is a linker which is chosen from linear and branched alkylchains and may be interrupted by at least one heteroatom atom and may besubstituted by at least one of a hydroxyl and a C₁-C₆ alkoxy radical,and may carry at least one ketone function; the ring members E, G, J, Land M, which are identical or different, are chosen from carbon, oxygen,sulphur and nitrogen atoms; n is an integer ranging from 0 to 4; m is aninteger ranging from 0 to 5; the radicals R, which are identical ordifferent, may be chosen from a group Z; a halogen atom; a hydroxylradical; a C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; aC₂-C₆ polyhydroxyalkyl radical; a nitro radical; a cyano radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxy radical; a C₁-C₆tri(C₁-C₆alkyl)silanealkyl radical; an amido radical; an aldehydo radical; acarboxyl radical; a C₁-C₆ alkylcarbonyl radical; a thio radical; a C₁-C₆thioalkyl radical; a (C₁-C₆ alkyl)thio radical; an amino radical; anamino radical protected by a group chosen from (C₁-C₅ alkyl)carbonyl,carbamyl, and (C₁-C₆ alkyl)sulphonyl; and groups NHR″ and NR″R′″ inwhich R″ and R′″, which are identical or different, are chosen from aC₁-C₆ alkyl radical, a C₁-C₆ monohydroxyalkyl radical and a C₂-C₆polyhydroxyalkyl radical; R₇ is chosen from a C₁-C₆ alkyl radical; aC₁-C₆ monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; aC₁-C₆ cyanoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a carbamyl(C₁-C₆ alkyl) radical; aC₁-C₆ (C₁-C₆ alkyl)carboxyalkyl radical; a benzyl radical; and a groupZ; R₈, R₉ and R₁₀, which are identical or different, are chosen from aC₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; a C₁-C₆ (C₁-C₆ alkoxy)alkyl radical; a C₁-C₆cyanoalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆amidoalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; and aC₁-C₆ aminoalkyl radical whose amine is protected by at least one of a(C₁-C₆ alkyl)carbonyl, amido, carboxyl and (C₁-C₆ alkyl)sulphonylradical; two of the radicals R₈, R₉ and R₁₀ may form, together with thenitrogen to which they are attached, a ring chosen from saturated 5- and6-membered carbon-containing rings which may contain at least oneheteroatom, wherein said rings may contain a substituent chosen from ahalogen atom; a hydroxyl radical; a C₁-C₆ alkyl radical, a C₁-C₆monohydroxyalkyl radical; a C₂-C₆ polyhydroxyalkyl radical; a nitroradical; a cyano radical; a C₁-C₆ cyanoalkyl radical; a C₁-C₆ alkoxyradical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; an amido radical;an aldehydo radical; a carboxyl radical; a C₁-C₆ ketoalkyl radical; athio radical; a C₁-C₆ thioalkyl radical; a (C₁-C₆ alkyl)thio radical; anamino radical; and an amino radical protected by a group chosen from(C₁-C₆ alkyl)carbonyl; carbamyl and (C₁-C₆ alkyl)sulphonyl radical; oneof the radicals R₈, R₉ and R₁₀ may be chosen from a second group Z,identical to or different from the first group Z; R₁₁ may be chosen froma C₁-C₆ alkyl radical; a C₁-C₆ monohydroxyalkyl radical; a C₂-C₆polyhydroxyalkyl radical; an aryl radical; a benzyl radical; a C₁-C₆aminoalkyl radical; a C₁-C₆ aminoalkyl radical whose amine is protectedby at least one of a (C₁-C₆ alkyl)carbonyl, a carbamyl, and a (C₁-C₆alkyl)sulphonyl radical; a C₁-C₆ carboxyalkyl radical; a C₁-C₆cyanoalkyl radical; a C₁-C₆ carbamylalkyl radical; a C₁-C₆trifluoroalkyl radical; a C₁-C₆ tri(C₁-C₆ alkyl)silanealkyl radical; aC₁-C₆ sulphonamidoalkyl radical; C₁-C₆ (C₁-C₆ alkyl)carboxyalkylradical; a C₁-C₆ (C₁-C₆ alkyl)sulphinylalkyl radical; a C₁-C₆ (C₁-C₆alkyl)sulphonylalkyl radical; a C₁-C₆ (C₁-C₆ alkyl)ketoalkyl radical; aC₁-C₆ N-(C₁-C₆ alkyl)carbamylalkyl radical; and a C₁-C₆ N-(C₁-C₆alkyl)sulphonamidoalkyl radical; a and y are integers equal to 0 or 1;with the following conditions: in the unsaturated cationic groups offormula (II): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J orL, y can adopt the value 1 only 1) when the ring members E, G, J and Lare simultaneously a carbon atom and when the radical R₇ is carried bythe nitrogen atom of the unsaturated ring; or 2) when at least one ofthe ring members E, G, J and L is chosen from a nitrogen atom to whichthe radical R₇ is attached; in the unsaturated cationic groups offormula (III): when a=0, the linker D is attached to the nitrogen atom,when a=1, the linker D is attached to one of the ring members E, G, J, Lor M, y can adopt the value 1 only 1) when at least one of the ringmembers E, G, J, L and M is chosen from a divalent atom and 2) when theradical R₇ is carried by the nitrogen atom of the unsaturated ring; inthe saturated cationic groups of formula (IV): when a=0, then the linkerD is attached to the nitrogen atom which carries the radicals R₈ to R₁₀,when a=1, then two of the radicals R₈ to R₁₀, together with the nitrogenatom to which they are attached, form a ring chosen from 5- and6-membered saturated rings , and the linker D is carried by a carbonatom of the said ring; X⁻ is chosen from monovalent and divalent anions;with the proviso that at least one of R₁, R₂ and R₃ is a group Z.